This has been ruled out by the Conservatives but a new compromise deal which would limit the amount that could be saved annually is now under consideration.

The plan could mean that savers would only be allowed to save a maximum of £40,000 or even £30,000 annually in a pension – and receive tax relief on their investments. The £40,000 threshold would save the Exchequer about £600 million annually while the £30,000 limit would raise £1.8 billion.

However, it would undermine the retirement planning of thousands of professional Britons.

According to The Financial Times, the scheme was discussed at a meeting of the quad of senior Conservatives and Liberal Democrats yesterday. In his first emergency budget in 2010, George Osborne cut the maximum annual pension contribution from £255,000 to £50,000.

The long-standing Lib Dem demand to cut tax relief on pension contributions by higher-rate taxpayers is also said to still be part of the Coalition discussions, but is believed to have little chance of winning Conservative support.

At the moment, for every 60p saved in a pension by a higher-rate taxpayer, the Government contributes 40p in tax relief to make it up to £1. The Liberal Democrats believe this should be reduced to 20p for the better-off, in line with the basic rate of income tax.

Earlier this year, Danny Alexander, the Liberal Democrat chief secretary to the Treasury told the Daily Telegraph: "If you look at the amount of money that we spend on pensions tax relief, which is very significant, the majority of that money goes to paying tax relief at the higher rate,”

The pension proposal comes amid increasingly tense negotiations within the Coalition over new wealth taxes. The Liberal Democrats are threatening to veto a freeze on benefits without an additional levy on richer Britons.

David Cameron indicated yesterday that he would rule out Lib Dem plans for new council tax bands on homes worth more than £1 million.

A spokesman for the Prime Minister said the government had ruled out a new top council tax band or a “mansion tax” on properties worth millions of pounds.

However, Number 10 refused to deny suggestions that Mr Osborne could announce a new increase in stamp duty for high-value property sales in his Commons statement next month.

“Issues of tax are a matter for the Chancellor and we've got the Autumn Statement only a few weeks away,” the Prime Minister’s spokesman said.

“But as a point of principle we've made it clear that those with the broadest shoulders should bear the greatest burden. We don't think that people who've worked hard and saved up to buy a home should be hit with a mansion tax.

“And we've no plans to introduce new council tax bands either – we've ruled out a re-evaluation in the Parliament.”

Last year Mr Osborne announced a new 5 per cent tax on property sales of more than £1 million and a 7 per cent charge on sales of homes worth more than £2 million.

There are few signs that the measures have deterred buyers and ministers are believed to be open to further increases.

On Sunday, Vince Cable, the Lib Dem Business Secretary said property taxes were “the obvious place to go” to tax wealth.

“There needs to be a sense of fairness, and these best-off people in society have got to contribute more,” he told the BBC. “There are arguments around taxation, about property taxation. It'll all be resolved in the next few weeks.”

However, the London Mayor, Boris Johnson, warned that the Coalition should collect more money from companies like Google instead of considering “absurd” plans for a mansion tax on individuals.

Mr Johnson said many Londoners living in seemingly expensive homes actually had little disposable income.

“We should have taxes that are low but fair and it is absurd to be suddenly whacking up taxes on cash poor people who happen to inhabit expensive houses in London when firms like Google are paying zero,” he said.